Sex steroid hormones as modulators of neurovascular function

心血管系统是身体适应日常生活压力源的关键组成部分。事实上，各种各样的刺激都能引起急性和必要的心血管反应，包括说话、唱歌、走路、站立、锻炼等等。在心血管系统中，交感神经系统（“战斗或逃跑”系统）和控制许多反射反应的抵抗血管之间的相互作用。然而，关于这些重要的调节机制，特别是性别和性激素对这些机制的影响，仍有很多有待了解的地方。***虽然现在人们普遍认为心血管控制机制在男性和女性之间经常有所不同，但我们仍然对男女之间心血管反射的差异（即站立和运动反应的比较）以及为什么这种控制机制在男性和女性之间会有所不同了解甚少。后者可能包括性激素，尤其是雌激素和黄体酮。经过几十年的研究，雌激素对血管的影响已经得到了很好的证实。然而，我们对雌激素影响交感神经系统的程度知之甚少，对黄体酮的交感神经或血管作用的了解就更少了。因此，这项提议的目的是阐明雌激素和黄体酮对年轻健康人类的交感神经和血管的影响。这些研究将为交感神经系统和血管系统之间复杂的相互作用提供新的见解，特别是在女性中。我们还设计了这些实验，使我们能够区分雌激素和黄体酮的独立作用。将这些方法与我们的反射性心血管调节的综合测量相结合，我们的目标是提供雌激素和孕激素在控制交感神经系统反射激活和外周脉管系统下游后果中的作用的新见解。***这些研究的结果将增强我们对人体对日常生活中不同压力源的反应的基本理解。

The cardiovascular system is a critical component of the body's adaptations to the stressors of daily life. Indeed, a wide variety of stimuli evoke acute and necessary cardiovascular responses, including talking, singing, walking, standing, exercising, and many more. Within the cardiovascular system, it is interactions between the sympathetic nervous system (the “fight or flight” system) and the resistance blood vessels which govern many of these reflex responses. However, there remains a great deal yet to be understood regarding these important regulatory mechanisms, particularly with respect to the effects of sex and sex hormones on these mechanisms. ***While it is now widely acknowledged that cardiovascular control mechanisms often differ between men and women, we still possess a poor understanding of which cardiovascular reflexes differ between the sexes (i.e. comparisons of the responses to standing versus the responses to exercising) as well as why such control mechanisms would be different between men and women. Likely candidates for the latter include the sex hormones, particularly estrogen and progesterone. The effects of estrogen on blood vessels has been well established by decades of study. However, much less is known regarding the extent to which estrogen affects the sympathetic nervous system, and even less is known regarding the sympathetic or vascular effects of progesterone. ***Therefore, the purpose of this proposal is to shed light on the sympathetic and vascular effects of estrogen and progesterone in young healthy humans. These studies will provide novel insight into the complex interactions which occur between the sympathetic nervous system and the vascular system, particularly in women. We have also designed these experiments to allow us to differentiate between the independent effects of estrogen and progesterone. Combining these methodologies with our comprehensive measures of reflex cardiovascular regulation, we aim to provide novel insight into the roles of estrogen and progesterone in governing the reflex activation of the sympathetic nervous system and the downstream consequences in the peripheral vasculature. ***The results from these studies will enhance our fundamental understanding of the human body's responses to different stressors of daily life in both men and women.